ECAT Pre General Science MCQ Test With Answer for Mathematics Chapter 9

An integer is chosen at random from the number ranging from 1 to 50. the probability that the integer chosen is a multiple of 2 or 3 or 10 is

• 3 / 10 A
• 5 / 10 B
• 7 / 10 C
• 9 / 10 D

Three unbiased coins are tossed. Then the probabilities of getting two heads is

• 3/8 A
• 1/8 B
• 1/4 C
• None of these D

• 
  A
• 
  B
• 
  C
• 
  D

A combination lock on a suitcase has 3 wheels each labeled with nine digits from 1 to 9. If an opening combination is a particular sequence of three digits with no repeats, the probability of a person guessing the right combination is

• 1 / 500 A
• 1 / 504 B
• 1 / 252 C
• 1 / 250 D

n!/(n-1)!=

• n A
• n! B
• (n-1)! C
• 0! D

Number of permutations of n distinct objects taken r(<n - 3) at a time which exclude 3(<n) particular objects is

• 3! P(n, r - 3) A
• P(n, 3) P(n, r - 3) B
• P(r, r)P(n, r - 3) C
• P(n - 3, r) D

If two balls are drawn from a bag containing 3 white, 4 black and 5 red balls. Then the probability that the drawn balls are of different colours is

• 1 / 66 A
• 3 / 66 B
• 19 / 66 C
• 47 / 66 D

How many 3 digit numbers can be formed by using each one of the digit 2, 3, 5, 7, 9 only once?

• 15 A
• 24 B
• 60 C
• 120 D

A bag contains 7 whit, 5 black and 4 rd balls. If two balls are drawn at random from the bag, the probability that they are not of the same color is

• 73 / 120 A
• 83 / 120 B
• 67 / 120 C
• 43 / 120 D

A coin is tossed. If head comes up, a die is thrown but if tail comes up, the coin is tossed again. The probability of obtaining a head and an even number is

• 1/8 A
• 2/8 B
• 3/8 C
• None of these D

If 4 ⁶P_r= ⁶P_r+1, then r is equal to

• 4 A
• 3 B
• 2 C
• 1 D

The sample space for tossing a coin once is

• {T, T} A
• {H, H} B
• {H, T} C
• None of these D

For a positive integer n

• n! = n(n + 1) A
• n! = n(n+1)! B
• n! = n(n - 1 ) C
• n! = n(n - 1)! D

• 
  A
• 
  B
• 
  C
• 
  D

The probability that the sum of dots appearing in two successive thrown of two dice, in every time 7 is

• 1/5 A
• 1/36 B
• 1/7 C
• 1/63 D

• 36 A
• 360 B
• 24 C
• 6 D

If for two events A and B , P(A∪B)=1,then events A and B are

• Certain events A
• Mutually exclusive B
• Complementary events C
• Independent D

• 120 A
• 5 B
• 4 C
• 6 D

Five engineering, four mathematics, two chemistry books are placed on a table at random.The probability that the books of each kind are all together is

• 
  A
• 
  B
• 
  C
• 
  D

• 5 A
• 20 B
• 9 C
• 4 D

• 1.5 A
• 1.2 B
• 8 C
• None of these D

An event having more than one sample point is called

• Certain event A
• Compound event B
• Simple event C
• None D

All letters of the word "AGAIN" are permuted in all possible ways and the words so formed (with or without meaning) are written as in dictionary, then the 50th word is

• NAAGI A
• NAAIG B
• IAANG C
• INAGA D

Probability of an impossible event is

• 0 A
• -1 B
• 1 C
• ∞ D

• 6 A
• 360 B
• 120 C
• 24 D

• n! A
• 0! B
• 1 C
• None of these D

How many 6-Digit number can be formed without repairing any digit from the digits 0,1,2,3,4,5

• 720 A
• 600 B
• 120 C
• 6-5! D

The number of the diagonals of a 6 sided figure is

• 15 A
• 21 B
• 9 C
• 6 D

nCn-r is equal to

• n! A
• n-1Cr B
• nCr C
• None of these D

How many arrangements of the letters of the word MI SSI PPI, taken all together can be made?

• 
  A
• 
  B
• 
  C
• 
  D